Hydrangea quercifolia Bultinks Giant Flowers

Hydrangea quercifolia, or oakleaf hydrangea, is a bush with large lobed leaves. It is a decorative plant all year round, first and foremost because of the unique design of its large lobed leaves, and then because of its flowering in large white panicles that lasts for several months, from early summer to September or October. And finally, its autumn foliage that turns a rich reddish-purple before falling. Moreover, its exfoliating bark is truly decorative in winter, with a lovely cinnamon colour. Cultivars are most commonly found in our gardens, but the species itself is very interesting.

Hydrangea quercifolia, from the Hydrangeaceae family, is mainly native to the southwest United States, particularly the Mississippi Valley. It grows on cliffs, in moist woods, ravines, and along riverbanks, from Georgia to Louisiana, passing through Florida. It is a large deciduous bush, reaching up to 4 m (13.1 ft) in height in its natural habitat and spreading up to 3.5 m (11.5 ft) wide through the production of shoots. It is characterised by a deep root system and large lobed leaves, which are supposed to resemble the leaves of the American red oak (Quercus rubra). In reality, the leaves of the red oak are more thread-like and smoother. The leaves of the hydrangea are wide and slightly rough, with more pronounced veins. Measuring 25 cm to 30 cm (9.8 in to 11.8 in) long, its leaves are almost as wide and deeply lobed, forming large characteristic lobes.

It is appreciated for its beautiful autumn colours and its flowering in large upright white panicles, 20 cm to 25 cm (7.9 in to 9.8 in) long, composed of small powdery fertile flowers surrounded by larger sterile florets that turn pink towards the end of the season. In the garden, it is one of the easiest hydrangeas to grow: it is hardy beyond -20° C (-4° F), tolerates some limestone in the soil, and can withstand heat and periodically dry soils in summer if they are planted deeply enough.

A spring-cleaning pruning is sufficient to remove the faded inflorescences from the previous autumn and possibly limit its growth, as it tends to spread quite wide!

The oakleaf hydrangea appreciates slightly sunny positions that enhance its autumn colours and abundant flowering, dappled light from tree foliage or even shade in hot climates. It can be used in borders, as a solitary plant in a small garden or along a path, and in a loose hedge, but it does not tolerate container cultivation well. It can be grown with other hydrangeas, but since it does not require ericaceous soil, it can also be planted alongside many other bushes that thrive in neutral soils. As it blooms in summer until late in the season, it can be paired with spring-flowering shrubs. The small Lilac 'Superba' with its highly fragrant small pink flowers, Physocarpus 'Diable d'Or' with its purple foliage that contrasts with the green of the hydrangea, the lovely Spiraea 'Grefsheim' or Bridal Wreath, with its delicate branches covered in white flowers, will all be good companions for the early season. For the summer, the narrow foliage and slightly hazy blue flowers of Ceanothus 'Gloire de Versailles' will bring lightness alongside our Hydrangea quercifolia.